Go on the roads of the Tour de France, with three well known passes on the programme.
The end of the Hundsrück sets the "tone" for this ode to the mountains. The Ballon d'Alsace is even longer, and you will climb it on its so said most difficult side.
At the exit of the Bussang, and before your return to Alsace, do not hesitate to drink some water at the Marie spring. It offers an iron-rich water that will help you to regain your strength!